I-phone play

[53driver]

Just to be clear my question is why the small pin plays much lower volume than the radio or the USP port.

The cubby connector "cares" what volume the controlling source is set to, whereas the USB port doesn't care.
Have you tried adjusting the media volume on your iPhone to "Full-Tilt-Boogie"?
It may not sound well at that level, and could possibly overload the input on the amp, so please adjust volumes responsibly....
Cheers,
Steve

[2wheelsforme]

Yep the phone is at max and still low volume. Glad to hear the USB also charges. I will work it out when I start to install the Zumo 590. Plan to take this thing apart to make the additions and changes I want after I receive the ordered parts and the manual.

[MisterB]

Does the 1/8" plug insert fully into your phone? Sometimes a case will prevent that.
If you're not sure, try moving the balance to either side on the iPhone or the B and see if you have signal.
Try another audio source with 1/8" output to see if you can eliminate the phone or the AUX input.
If the AUX input always sounds bad it could be that 2 of the 3 wires that connect to the factory wiring harness have been reversed which would lead to your L/R being out of phase.

[2wheelsforme]

That sounds like some good advice. I will try those things when get back home from Christmas in Prairieville LA.

[53driver]

Does the 1/8" plug insert fully into your phone? Sometimes a case will prevent that.
If you're not sure, try moving the balance to either side on the iPhone or the B and see if you have signal.
Try another audio source with 1/8" output to see if you can eliminate the phone or the AUX input.
If the AUX input always sounds bad it could be that 2 of the 3 wires that connect to the factory wiring harness have been reversed which would lead to your L/R being out of phase.

I keep forgetting to advise people to check for this! Well done, MisterB!
Hopefully that solves the issue!
Cheers,
Steve

[ReserveBum]

Not sure if this is your issue but......On using the 3.5mm plug/connector. I was using my earbuds with the Honda 5 pin connector and a headphone adapter and when the male end is plugged all the way in, I lost most of my volume. Turns out that there is a conductive piece at the base of the plug and when it came in contact with the receptacle, it would lower the volume. Had to pull connector out @ 1/16"

[2wheelsforme]

I don't know what happened but no problem now.